TWI610971B - Diene rubber composition configured to be vulcanized at lower temperature; and manufacturing process of rubber article from the same - Google Patents

Abstract

The invention provides a method for forming an article from a diene rubber, comprising: providing a raw diene rubber substance containing a 1,2-polybutadiene rubber component; and adding the raw diene rubber substance as a vulcanizing agent. Peroxide; soften the raw diene rubber at a first temperature not exceeding 200 ° C; and make the diene rubber at a second temperature not exceeding 200 ° C while bringing the diene rubber into contact with the surrounding atmosphere Vulcanization; and forming an object from the vulcanized diene rubber.

Description

Diene rubber composition configured to be vulcanized at low temperature and rubber article made therefrom

The present invention relates to a method for forming a diene rubber article, and more particularly, it relates to a method for forming a diene rubber article vulcanized at a low temperature. The present invention also relates to an article prepared by the method and a raw diene rubber material used in the method.

Rubber is an elastic polymeric substance and is classified as one of thermoplastic elastomers (TPE). The physical and chemical properties of rubber are different from other resins and polymer oils. Diene rubber is a rubber having a double bond in the main chain. In practice, diene rubber generally needs to be vulcanized.

A method for converting or modifying raw diene rubber materials by vulcanization. The vulcanization method uses some vulcanizing agents and / or heating to create strong bonds or crosslinks between the chain molecules in the diene rubber. The vulcanization method modifies the raw diene rubber to increase some mechanical properties, such as elasticity and tensile strength, and to reduce plastic flow. Vulcanization also prevents the diene rubber from expanding at least to some extent.

For many years, sulfur has been used as the most commonly used vulcanizing agent in the field of rubber manufacturing. However, sulfur-based vulcanizing agents, such as sulfur powder (S ₈ ), require higher temperatures and longer periods of time to promote the vulcanization process of raw diene rubber.

Conventional diene rubber compositions generally require a relatively large amount of sulfur-based vulcanizing agent for vulcanization, and then the final rubber will be colored or tarnished by sulfur. The rubber composition containing a large amount of sulfur thus obtained will have poor turbidity or yellowing.

Using sulfur as a vulcanizing agent may cause haze on the surface of rubber during storage. This blur may contaminate the surrounding environment around the rubber storage container or tank. In addition, the sulfur content of conventional rubber articles may not meet the industrial or environmental standards of various countries and regions. Large amounts of sulfur can also cause malodors.

The use of peroxides for rubber vulcanization has been described previously to reduce or eliminate the amount of sulfur used to mitigate the toxic or harmful effects of sulfur.

Patent Document 1 (JPH04275352A filed by NOF Corp.) discloses a conventional method for vulcanizing an ethylene propylene rubber (EPR) using a peroxymonocarbonate.

Patent Document 2 (JPS4615420B filed by Nippon Kayaku) discloses a conventional method for vulcanizing EPDM using peroxycarbonate.

Patent Document 3 (JPH04293946A) and Patent Document 4 (JPH06100741A) of the JSR application disclose some conventional EPR compositions using dicumyl peroxide for vulcanization.

Citation List Patent literature

Patent Document 1: Japanese Patent Laid-Open Publication No. H04-275352

Patent Document 2: Japanese Patent Examination Publication No. S46-015420

Patent Document 3: Japanese Patent Laid-Open Publication No. H04-293946

Patent Document 4: Japanese Patent Laid-Open Publication No. H06-100741

If the vulcanization method is performed in an ambient atmosphere (that is, an open type method), the conventional diene rubber composition cannot be industrially formed into a satisfactory article. With the use of sealed molds Unlike mold making methods, such as injection molding methods and pressure vulcanization methods, during the open type vulcanization method using peroxides, the raw rubber material naturally contacts the surrounding atmosphere, which usually contains oxygen. Oxidants, such as oxygen-derived oxygen radicals, sometimes forcefully attack double bonds located on the main chain of diene rubber molecules in the presence of peroxides. Then the molecular chain is cut and the rubber surface degrades and becomes sticky. Therefore, in practice, this conventional method can only produce diene rubber articles which are not industrially or commercially useful. In addition, conventional diene rubber compositions generally have lower fluidity, and melt failure occurs when they undergo extrusion. Conventionally, conventional diene rubbers are not vulcanized in a developmental process, but some resin (non-rubber) can be extruded and formed using peroxides. In the field of rubber manufacturing, the skilled person should understand that, in practice, the combination of diene rubber and peroxide cannot be extruded well.

The above patent documents 1 to 4 only propose to use EPR instead of diene rubber because EPR does not have a double bond on the main chain. Specifically, Patent Document 3 discloses in paragraph 0002 that the conventional rubber is destroyed by a conventional crosslinking method using an organic peroxide when the conventional rubber is in contact with air (for example, oxygen), and the crosslinked rubber article obtained thereby Has a sticky surface. The above conventional studies have not solved the problems caused by the open type vulcanization method using peroxides.

In addition, pure EPR is generally weaker to oil, has a relatively slow vulcanization rate, and requires higher temperatures (such as more than 200 ° C) and longer periods of time (such as more than 20 minutes) to be vulcanized by peroxide.

There is a need to develop a novel method for making diene rubber articles using an open type vulcanization method and a novel raw diene rubber composition that can be used in the novel method.

The present invention provides that, unexpectedly, a diene rubber substance can be vulcanized and formed into an article at low temperatures with peroxides in an open process.

In one embodiment, the present invention provides a method for forming an article from a diene rubber, the method comprising the steps of:-providing a raw diene rubber substance comprising a 1,2-polybutadiene rubber component; -Adding peroxide as a vulcanizing agent to the raw diene rubber substance;-softening the raw diene rubber at a first temperature not exceeding 200 ° C;-under contacting the diene rubber with the surrounding atmosphere, Vulcanizing the diene rubber at a second temperature not exceeding 200 ° C; and-forming an article from the vulcanized diene rubber.

In another embodiment, the present invention also provides a diene rubber article manufactured by the above method.

In yet another embodiment, the present invention also provides a diene rubber composition configured to undergo extrusion, the composition comprising:-a raw diene rubber comprising a 1,2-polybutadiene rubber component Substances; and-peroxides as vulcanizing agents.

The present invention is capable of vulcanizing a diene rubber substance and forming a diene rubber object therefrom by an open method at a relatively low temperature. The method of the invention can also make the rubber have good fluidity to reduce or eliminate the phenomenon of melt failure.

Figure 1 illustrates an image of an extruded tube made from sample # 31.

Examples of the present invention will be explained in detail, but the method of the present invention and the articles prepared using the method are not limited to these examples.

definition

The term "diene rubber substance" means a rubber substance containing at least one diene rubber component having a double bond in the main chain. Diene rubber materials may include, but are not limited to, isoprene rubber (IR), butadiene rubber (BR), 1,2-polybutadiene rubber (or 1,2-polybutadiene elastomer) , Styrene-butadiene rubber (SBR), acrylonitrile butadiene rubber (NBR), hydrogenated nitrile rubber (HNBR), chloroprene rubber (CR) and any grade of natural rubber (NR). in In one embodiment, the diene rubber substance may include only one or more diene rubber components. In another embodiment, the diene rubber substance may include a combination of one or more diene rubber components and one or more non-diene rubber components. Diene rubbers can include conjugated and non-conjugated diene rubbers.

The phrase "raw rubber" in this specification means a rubber composition that has not been substantially vulcanized.

The term "half-life temperature of peroxide" means the temperature required to half-decompose one of a given amount of peroxide in a dilute solution. For organic peroxides, this phenomenon follows the formula: ln (C ₀ / C _t ) = K _d t

Wherein C ₀ is the initial concentration of organic peroxide; C _t for the peroxide concentration at time T; and K _d is the thermal decomposition rate constant. The half-life t _1/2 is calculated by: t _1/2 = (ln2) / (K _d )

Half-life temperature is generally expressed in this technology as a 1-minute half-life temperature, a 1-hour half-life temperature (T1), or a 10-hour half-life temperature (T10).

The term "mold / molding" means in this specification that a rubber substance is converted into an object and may include vulcanization and / or forming steps. In one embodiment, the molding or forming process may be performed using a head die or an extrusion die.

The term "transparent" means that the transmitted light passing through the object mainly includes specular transmission, and the ratio of visible light transmitted by the specular surface is relatively large. In this application, transparency is determined by the value of turbidity or the total light transmittance. Objects that do not have "transparency" as defined above may be referred to as "opaque" or "translucent".

The term "turbidity" means the degree of haze of a transparent material measured according to JIS K7163 (or ISO 14782). The turbidity value is determined as the percentage of transmitted light that deviates from incident light by an angle of 0.044 rad or more by forward scattering.

The term "TT" means "total light transmittance" and means that according to JIS K7361-1 (or ISO 13468-1) Measured ratio of light beam passing through transparent material. The value of the total light transmittance is measured as the ratio of the total transmitted light flux to the parallel incident light flux on the test object.

The term "A-type durometer hardness" or "Hs" means the hardness of a rubber substance measured according to JIS K6253. In this specification, the Hs value is determined by a procedure in which a plunger is constantly pushed on a test object and the depth of the plunger being pushed in the object at 0 or 30 seconds after the push is measured.

The term "tear strength" means the tear strength of a rubber substance measured according to JIS K6252. In this specification, the tear strength value is measured by using a 2 mm thick sheet of test material and converted into N / mm units.

The term "tensile force at break", "tensile force" or "Tb" means the maximum stress at break of a test strip stretched at a constant rate measured in accordance with JIS K6252. In this specification, the tensile force value is calculated by dividing the maximum stress experienced on the test strip by the initial cross-sectional area of the strip and converting the resulting value into MPa units.

The term "elongation at break", "elongation" or "Eb" means the deformation of the stretched tape along the stretch (length) axis measured in accordance with JIS K6251 (ISO37). In this specification, the elongation value is expressed as the ratio of the length of the elongation of the strip to the initial length of the strip and is expressed as a percentage.

The term "tensile stress" or "modulus" means the stress when the test strip is extended by a given length, measured according to JIS K6251 (ISO37). In this specification, the modulus value is calculated by dividing the load on a test strip extending a given length by the cross-sectional area of the strip and converting the resulting value into MPa units. The modulus of elongation of 100%, 300% or 500% can be called "M100", "M300" or "M500", respectively.

The term "Mooney viscosity" means the viscosity of unvulcanized rubber measured according to JIS K6300-1 or ASTM D 1646. In this specification, the Menner viscosity value is measured by measuring the Menner viscosity in accordance with the standard in JIS K6300-1.

The term "refractive index" means, for example, that light measured in accordance with JIS K7142 Index of speed in matter.

The term "vinyl content" refers to the amount of conjugated diene polymerized via 1,2-addition (for butadiene; for isoprene, it is 3,4-addition). Although pure "vinyl" is formed only by the 1,2-addition polymerization of 1,3-butadiene, the 3,4-addition polymerization of isoprene (and similar additions of other conjugated diene) The effect on the final characteristics of the block copolymer will be similar. As a result of the above addition reaction, pendant vinyl groups will be produced on the polymer backbone. The vinyl content of a polymer can be measured using techniques known in the art, such as proton NMR.

By changing the relative amount of the partitioning agent will effectively control the vinyl content. It should be understood that the partitioning agent serves two purposes: it controls the distribution of the monoalkenyl arene and the conjugated diene, and it controls the microstructure of the conjugated diene. A suitable ratio of partitioning agent to lithium is disclosed in US Patent No. Re 27,145, the disclosure of which is incorporated herein by reference.

As used herein, unless otherwise stated, the term "molecular weight" refers to the true molecular weight of a block of a polymer or copolymer, expressed in g / mol. The molecular weights mentioned in this specification and the scope of the patent application can be measured by gel permeation chromatography (GPC) using polystyrene calibration standards, such as according to ASTM 3536. GPC is a well-known method in which polymers are separated according to their molecular size, with the largest molecules dissolving first. The chromatograph was calibrated using a commercially available polystyrene molecular weight standard. The molecular weight of a polymer measured using the GPC thus calibrated is the equivalent molecular weight of styrene, also known as the apparent molecular weight. When the styrene content of the polymer and the vinyl content of the diene segment are known, the styrene equivalent molecular weight can be converted to the true molecular weight. The detector used is preferably a combined ultraviolet and refractive index detector. The molecular weight expressed herein is measured at the peak of the GPC trace, converted to the true molecular weight, and is often referred to as the "peak molecular weight." When expressed in terms of apparent molecular weight, it is determined in a similar manner, but without taking into account the composition of the block copolymer and subsequent conversion to the true molecular weight.

In this specification, unless otherwise stated, the words "comprising", "including" and "containing" mean that an article or component implies or has one or more ingredients. The words The spirit can include both internal and external additions.

In this specification, where a value is added before the word "about", "approximately" or "appropriately", the value may include a tolerance of at least +/- 10%.

In this specification, reference numbers of standards such as ASTM, ISO, and JIS are those standards known to those skilled in the art at the time of the application or priority date of this application.

Overview of peroxides

In the embodiment of the present invention, any peroxide may be used to vulcanize the raw diene rubber substance, as long as the vulcanization method is successfully completed in an open environment where the rubber is brought into contact with the surrounding atmosphere. The peroxides may include organic and inorganic peroxides. For the method of the present invention, organic peroxides are generally preferred due to appropriate half-life temperatures and relatively small trace impurities.

Organic peroxides can include, but are not limited to, hydroperoxides (R ¹ -OOH), dialkyl peroxides (R ¹ -OOR ² ), peroxyesters (R ¹ -C (O) -OOR ² ), Difluorenyl peroxide (R ¹ -C (O) -OOC (O) -R ² ), peroxydicarbonate (R ¹ -OC (O) -OOC (O) -OR ² ), peroxide Oxyketals (R ¹ -OOC (-R ³ ) (-R ⁴ ) -OOR ² ) and ketone peroxides (HOOC (-R ¹ ) (-R ² ) -OOH). R ¹ , R ² , R ³ and R ⁴ may independently or individually represent aliphatic, cyclic having 1 to 24 carbon atoms, preferably having 1 to 12 carbon atoms, and more preferably having 1 to 10 carbon atoms. Aliphatic or aromatic groups. R ¹ , R ² , R ³ and R ⁴ may be branched or unbranched and may be further substituted with halo, C ₁ to C ₈ aliphatic, cycloaliphatic or aromatic groups.

Organic peroxides can include, but are not limited to, diisobutylphosphonium peroxide, cumyl peroxyneodecanoate, di-n-propyl peroxydicarbonate, di-second butyl peroxydicarbonate, 1,1,3,3-tetramethylbutyl peroxyneodecanoate, bis (4-third butylcyclohexyl) peroxydicarbonate, bis (2-ethylhexyl) peroxydicarbonate , Third peroxy neodecanoate, third butyl peroxy neodecanoate, third butyl peroxyheptanoate, third hexyl peroxypivalate, third perpervalerate Butyl ester, bis (3,5,5-trimethylhexamethane) peroxide, dilauryl peroxide, peroxy-2-ethylhexanoic acid 1,1,3,3-tetramethylbutyl ester , Disuccinate peroxide, 2,5-dimethyl-2,5-bis (2-ethylhexylperoxy) hexane, perox-2-ethylhexanoic acid third hexyl ester, bis (4-methyl peroxide) Benzamidine), tert-butyl peroxy-2-ethylhexanoate, bis (3-methylbenzidine) peroxide, dibenzyl peroxide, 1,1-bis (third butyl) Peroxy) -2-methylcyclohexane, 1,1-bis (third hexylperoxy) -3,3,5-trimethylcyclohexane, 1,1-bis (third hexyl peroxy) Oxy) cyclohexane, 1,1-bis (third butylperoxy) cyclohexane, 2,2-bis (4,4-bis (third butylperoxy) cyclohexyl) propane, Peroxoisopropyl monocarbonate, third hexyl ester, third butylperoxymaleic acid, peroxy-3,5,5-trimethylhexanoic acid third butyl ester, peroxylauric acid third Butyl ester, third butyl peroxyisopropyl monocarbonate, third butyl peroxy-2-ethylhexyl monocarbonate, third hexyl peroxybenzoate, 2,5-dimethyl- 2,5-bis (benzylideneperoxy) hexane, third butyl peroxyacetate, 2,2-bis (third butylperoxy) butane, third butyl peroxybenzoate Base ester, 4,4-bis (third butylperoxy) n-butyl valerate, bis (2-third butylperoxyisopropyl) , Dicumyl peroxide, di-third hexyl peroxide, 2,5-dimethyl-2,5-di (third butylperoxy) hexane, third butyl cumene peroxide , Di-third butyl peroxide, p-menthane hydroperoxide, 2,5-dimethyl-2,5-bis (third butyl peroxy) hexyne-3, diisopropylbenzene Hydroperoxide, 1,1,3,3-tetramethylbutyl hydroperoxide, cumene hydroperoxide, third butyl hydroperoxide, 2,3-dimethyl-2, 3-diphenylbutane, bis-3.5.5-trimethylhexamidine peroxide, 1,3-bis (third butylperoxyisopropyl) benzene, and 1,6-bis (third butyl) -Peroxycarbonyloxy) hexane.

In one embodiment, from the viewpoint of boiling point and half-life temperature, the method of the present invention can preferably use peroxyesters, peroxydicarbonates, and peroxyketals.

In one embodiment, the 10-hour half-life temperature of the peroxide may preferably be about 20 ° C to about 190 ° C, preferably in the range of about 60 ° C to about 150 ° C, and more preferably in the range of about 80 ° C to about 120 ° C. Inside. If the 10-hour half-life temperature is too low, such as below 20 ° C, the diene rubber material may vulcanize (ie, scorch) prematurely. If the 10-hour half-life temperature is too high, for example, exceeding about 190 ° C, vulcanization may be too slow in practice.

In one embodiment, the 1-minute half-life temperature of the peroxide may be equal to or higher than It is about 100 ° C, preferably about 120 ° C or more, and more preferably about 140 ° C or more. If the 1-minute half-life temperature is too low, for example, below about 100 ° C, the diene rubber substance may be prematurely vulcanized and the rubber is difficult to squeeze out.

Based on the total mass of the material being 100 parts by mass, the material of the present invention may contain peroxides equal to or lower than about 20 parts by mass, preferably equal to or lower than about 15 parts by mass, and more preferably from about 0.1 to 10 The peroxide by mass is more preferably about 4 to 8 parts by mass.

In order to adjust the vulcanization temperature and rate, a peroxide may be combined with a sulfur-containing compound as long as the amount of sulfur does not harm the object of the present invention. For example, based on the total mass of the material being 100 parts by mass, the method of the present invention may use sulfur equal to or lower than about 1.0 part by mass, preferably equal to or lower than about 0.5 part by mass, and more preferably from about 0.05 to 0.5 Mass parts of sulfur. The amount of peroxide is preferably relatively low to reduce contamination in the resulting article and to suppress malodor during the manufacturing process. Some conventional techniques for the combination of peroxides and sulfur are disclosed in Manik, SP and Banerjee, S, Rubber Chemistry and Technology, July 1969, Vol. 42, No. 3, pages 744-758, which disclose The content is incorporated by reference.

Peroxides can be further combined with other free-radical cross-linking agents such as ethylene glycol dimethacrylate (EGDMA), trimethylolpropane methacrylate, triallyl isocyanurate, triallyl cyanurate Esters, diethylene glycol diacrylate and neophenylene glycol diacrylate.

In one embodiment, the peroxide may be a peroxide selected from the group consisting of alkali metal peroxides, metals in Group II of the Periodic Table, or including copper peroxide, titanium oxide, cerium peroxide, and chromium peroxide. Inorganic peroxides of heavy metal peroxides. The inorganic peroxide is preferably selected from the group consisting of calcium peroxide, strontium peroxide, barium peroxide, zinc peroxide, and cadmium peroxide. In this group, it is particularly preferred to use calcium peroxide or strontium peroxide. Preferably, such inorganic peroxides may be in the form of an oxide or glass.

Overview of diene rubber

In one embodiment, the diene rubber substance may include one or more diene rubber components. The rubber component can be prepared from, but not limited to, C ₄ to C ₂₀ olefins (including diolefins and α-olefins), preferably C ₄ to C ₁₂ olefins, and more preferably C ₄ to C ₈ olefins.

Olefins may include, but are not limited to, 1,2-butadiene, 1,3-butadiene, 2-methyl-1,3-butadiene (i.e., isoprene), 2,3- Dimethyl-1,3-butadiene, 1,3-pentadiene, 4-methyl-1-pentene, 1,3-hexadiene, 1,4-hexadiene, 1,3- Heptadiene, 4,6-dimethyl-1-heptene, 1,3-octadiene, 1,7-octadiene, 1,3-nonadiene, 1,3-decadiene, 1 , 9-decadiene, 1,3-dodecadiene, cyclopentene, cyclohexene, cyclooctene, dicyclopentadiene, norbornene, 5-ethylidene-2-norbornene , 5-vinylidene-2-norbornene and 5-methylene-2-norbornene. The olefin polymer may have any number average molecular weight, and, for example, may have a number average molecular weight of 100 g / mol to 100,000 g / mol. Olefins may also include vinyl aromatic hydrocarbons such as styrene, o-methylstyrene, p-methylstyrene, p-third butylstyrene, 2,4-dimethylstyrene, α-methylstyrene , Vinylnaphthalene, vinyltoluene, vinylxylene and mixtures thereof.

The term "non-diene rubber" means a rubber substance whose unit does not substantially have two double bonds. Non-diene polymers may include, but are not limited to, butyl rubber (IIR), fluorine rubber (FKM), ethylene-propylene rubber (EPM), ethylene-propylene-diene rubber (EPDM), urethane rubber (U) and silicone rubber (Q), and may further include any polymer made from any hydrocarbon known in the art.

Diene or non-diene rubbers may have some geometric isomers. The cis content (ratio) of these isomers can affect properties. The cis content can be measured by IR spectroscopy according to JIS 6230 or ISO 4650.

The degree of cis content depends on the type of rubber. For example, in the case of polyisoprene rubber (IR), a "low cis" diene rubber may have a cis content of about 90% to about 95%, and more typically about 90% to about 94% Cis content, and more typically has a cis content of about 90% to about 92%; and "high cis" diene polymers can have more than about A cis content of 95% typically has a cis content of about 95% to about 99%, and more typically has a cis content of about 96% to about 99%.

In the case of polybutadiene rubber (BR), a "low cis" rubber may have a cis content of about 20% to about 40%; a "high cis" rubber may have a cis content of about 94% to about 98% Formula content; and "medium cis" rubber may have intermediate cis content.

The high-cis diene rubber polymer may include, but is not limited to, LHIR-80 (neodymium-catalyzed high-cis polyisoprene rubber manufactured by Moaming Luhua; Mw: about 1800 to 2100 kg / mol; cis content: About 96% to 97%), LHIR-90 (neodymium-catalyzed high-cis polyisoprene rubber manufactured by Moaming Luhua; refractive index at 23 ° C: 1.519), Nipol IR2200 (non-neodymium manufactured by ZEON) Catalyzed and Ziegler-Natta catalyzed high-cis polyisoprene rubber; Mw: about 1700 kg / mol; cis content: about 98.5%; Menner viscosity: 82; at 23 ° C Refractive index: 1.519) and Nipol IR2200L (a non-neodymium-catalyzed and Ziegler-Natta catalyzed high-cis polyisoprene rubber manufactured by ZEON; Menner viscosity: 72).

Low-cis or medium-cis diene rubber polymers may include, for example, Cariflex IR0307 and Cariflex IR0310 (lithium-catalyzed polyisoprene manufactured by Kraton Polymers; cis content: about 87% to about 91%; at 23 ° C Refractive index: 1.519); Solprene 255 and Asaprene 755A (styrene elastomer made by Asahi Kasei); Diene 35NR, Diene 35RNF, Diene 55RNF, Diene 35NF, Diene 55NF and Diene 51 (medium manufactured by Firestone Polymers) Cis polybutadiene; cis content: about 40%; Menner viscosity: about 35 to about 55); and Nipol BR1241S and Nipol BR1242S (low cis 1,4-polybutadiene manufactured by ZEON; Meng Nano viscosity: about 35 to about 55).

1,2-polybutadiene can include (but is not limited to) JSR RB805, JSR RB810, JSR RB820, JSR RB830, and JSR RB840 (manufactured by JSR based on low crystallinity syndiotactic 1,2-polybutadiene thermoplastics Elastomer; 1,2-bond content: about 90% to about 96%). At 23 ℃ The refractive indices are as follows: JSR RB810: about 1.513; JSR RB820: about 1.515; JSR RB830: about 1.517.

The rubber polymer may preferably have low crystallizability to obtain appropriate flexibility. In the case of a polybutadiene block copolymer, the 1,2-addition ratio may preferably be about 30% or more to avoid crystallization after hydrogenation, and particularly to avoid excessive hardness at low temperatures.

The above rubber materials can be prepared by using any conventional inert hydrocarbon solvent known to be useful in the art. Suitable solvents may include, for example, linear or branched hydrocarbons, such as pentane, hexane, heptane, octane, and alkyl-substituted derivatives thereof; aliphatic cyclic hydrocarbons, such as cyclopentane, cyclohexene, cycloheptane Alkanes and their alkyl-substituted derivatives; aromatic hydrocarbons such as benzene, naphthalene, toluene, xylene and their alkyl-substituted derivatives; and hydrogenated aromatic hydrocarbons such as naphthalene and decahydronaphthalene.

Unless otherwise stated, the term "polymer" may also include modified polymers that have been modified with terminal modifiers. The modifier may include, for example, having one or more functional groups selected from the group consisting of amine, amidine, alkoxysilyl, isocyanate, imine, imidazole, urea, ether, carbonyl, carboxyl, hydroxyl, nitrile, and pyridyl compound of. Modifiers can include, but are not limited to, 3- (N, N-dimethylamino) propyltrimethoxysilane, 3- (N, N-diethylamino) trimethoxysilane, 3- (N , N-dimethylamino) propyltriethoxysilane, 3- (N, N-diethylaminopropyl) triethoxysilane, 3-glycidyloxypropyltrimethoxysilane, 2 -(4-pyridylethyl) triethoxysilane, N- (3-triethoxysilylpropyl) -4,5-dihydroimidazole and silicon tetrachloride.

In one embodiment, the diene rubber material may include lithium-catalyzed isoprene. The lithium catalyst may be an organic lithium catalyst. The organolithium catalyst may be a mono-, di-, tri- or tetra-substituted lithium compound which is mono-, di-, tri- or tetra-substituted by a C ₁ to C ₂₀ hydrocarbyl group or preferably a C ₂ to C ₈ hydrocarbyl group.

Organolithium catalysts can include, but are not limited to, alkyl lithium, such as methyl lithium, ethyl lithium, propyl lithium, n-butyl lithium, second butyl lithium, and third butyl lithium; aryl lithium, such as benzene Lithium and tolyl lithium; alkenyl lithium, such as vinyl lithium and propylene lithium; and alkylene lithium, Such as tetramethylene lithium and pentamethylene lithium.

In another embodiment, the diene rubber material may include a neodymium-catalyzed isoprene rubber component, that is, an isoprene rubber prepared by using a neodymium-containing catalyst. The neodymium-containing catalyst may include, but is not limited to, metal neodymium, and carboxylates, phosphates, phosphites, alkoxides, and diketone complexes of neodymium. The neodymium-containing catalyst used may be, for example, in the form of a solution in a hydrocarbon solvent.

The carboxylate of neodymium may include, but is not limited to, compounds containing a structure in which a carboxylate residue is bound to trivalent neodymium. The carboxylate may preferably be a saturated or unsaturated carboxylate having a C ₁ to C ₂₀ linear or branched alkyl or alkenyl group. The carboxylate may include, but is not limited to, 2-ethylhexanoic acid, neodecanoic acid, naphthenic acid, oleic acid, stearic acid, and benzoic acid.

Neodymium phosphates and phosphites may include, but are not limited to, [bis (2-ethylhexyl) phosphate] neodymium, [bis (1-methylheptyl) phosphate] neodymium, [2-ethylhexyl Mono-2-ethylhexyl phosphonate] neodymium, [bis (2-ethylhexyl) phosphinate] neodymium, [bis (1-methyl-heptyl) phosphinate] neodymium and [phosphine Acid (2-ethylhexyl) (p-nonylphenyl) ester] neodymium.

The alkoxide of neodymium may have a structure in which an alkoxy group is bonded to trivalent neodymium. The alkoxy group may preferably be a C ₁ to C ₂₀ alkoxy group, and may have, for example, a saturated or unsaturated, linear, branched, or cyclic skeleton. Alkoxy groups can include, but are not limited to, 2-ethyl-hexylalkoxy, olealkenylalkoxy, benzylalkoxy, stearylalkoxy, and phenoxy.

Neodymium β-diketone complexes, of course, contain β-diketone complexes such as acetoacetone complex, ethylacetoacetone complex, benzamidine acetone complex, and propionitrile acetone complex Compound and amyl acetone complex.

In one embodiment, the diene rubber substance may include rubber polymer components such as butadiene rubber (BR), 1,2-polybutadiene rubber, and styrene-butadiene rubber (SBR). These rubbers have similar characteristics and can be appropriately softened to exert suitable characteristics when they are mixed with polyisoprene rubber. In one embodiment, the rubber polymer may preferably include syndiotactic 1,2-polybutadiene or low-cis BR. Specifically, the rubber polymers having a syndiotactic structure are preferable because the structure can provide heat resistance.

In one embodiment, the raw rubber material of the present invention may include a 1,2-polybutadiene rubber component and a second rubber component. The second rubber component may be a diene rubber, a non-diene rubber, or both. In one aspect of this embodiment, the second rubber may include (but is not limited to) one or more selected from the group consisting of: butadiene rubber (BR), styrene butadiene rubber (SBR) , Acrylonitrile butadiene rubber (NBR), urethane rubber (U), ethylene propylene rubber (EPR) and natural rubber (NR). In one aspect of this embodiment, the amount of the 1,2-polybutadiene rubber component is not less than about 5 parts by mass, preferably about 5 to 95 parts by mass, and more preferably about 10 to 95 parts by mass Still more preferably, it is about 20 to 95 parts by mass, and the limitation is that the total amount of the rubber component is 100 parts by mass.

Other components

The material according to the embodiment of the present invention may further include other components or additives as long as the object of the present invention can be achieved. The other components may include, but are not limited to, colorants, modifiers, processing agents (e.g., lauric acid), antioxidants (e.g., monophenols, bisphenols, polyphenols, sulfur- and phosphorus-based compounds, such as by Irganox 800, Irganox 1010, Irganox 1726, Irgafos 168, and Irganox PS800), reducing agents, oxygen scavengers, light stabilizers, antacids, pH stabilizers, surface treatment agents, thermal stabilizers, colorants, fillers Agents (e.g., talc, clay, calcium carbonate, silica, fumed silica and carbon black), surfactants, gelling agents, biocides, UV absorbers (e.g., salicylic acid, dibenzyl Ketones, benzotriazoles, cyanoacrylates, and hindered amines), dust removers (for example, polyolefins such as polyethylene, silica, talc, calcium carbonate powder), flame retardants, and polyphosphoric acid.

Colorants can be used to give the object some color, such as clear blue, clear red, and clear green. Colorants can include any conventional colorants used in this technology, such as color pigments, extender pigments, anti-corrosive pigments, and functional pigments (e.g., phthalocyanine green, titanium, iron blue, iron oxide, lead hypooxide, and sulfurized Zinc).

In one embodiment, the method of the invention may include adding one or more pads Agents such as silica, fumed silica, clay and carbon black to improve the surface stability or surface smoothness of the obtained objects.

Based on 100 parts by mass of the total material, the composition of the embodiment of the present invention may include, for example, about 0.10 to about 10.0 parts by mass of other components, preferably about 0.20 to about 5.00 parts by mass of other components, and more preferably about 0.25 to about 2.00 parts by mass of other components. In yet another embodiment, the other components may be added in another amount.

In one embodiment, the material of the present invention may be substantially free of oil as a softening agent to prevent oil from oozing out. In another embodiment, the method of the present invention does not substantially use any processing oil to reduce contamination and improve the quality of the final article.

Softening method

The raw materials shown above can be placed in the equipment simultaneously, sequentially or continuously to soften them. These materials can also be prepared in the form of a master mix (MB). In one embodiment, the diene rubber substance to be poured may be in the form of a powder, pellets, composites, agglomerates, or semi-solids.

In one embodiment, the diene rubber substance and other materials may be fed into / onto devices such as extruders, hot rolls, and cylinders and softened.

In one embodiment, the method of the present invention can use an extruder such as a single screw extruder, a twin screw extruder and a multi-screw extruder, a planetary gear extruder, a plunger extruder, Kneader, disc group extruder and drum extruder. In one aspect of this embodiment, the extruder has a hopper, one or more feed zones, and a head die. In one aspect, raw rubber materials, peroxides, and other additives can be placed into the extruder simultaneously, sequentially, or continuously via a hopper. In another aspect, the raw materials can be poured separately from a separate inlet connected to each feed zone of the extruder. In one embodiment, the extruder may have one or more internal or external heaters to heat the target material.

In another embodiment, the raw materials may undergo processing by a calendering device. If the target object is in the form of a film or sheet, a calendering device may be preferred.

In yet another embodiment, the raw materials may be kneaded and then exposed to the surrounding atmosphere and heat to age. One of the methods may be called open-air steam aging ("Maki-Mushi" in Japanese), in which a raw rubber material is kneaded and adhered around a mandrel, and a damp cloth is placed around the material, and the material is entangled. The material is steamed to cure it.

In one embodiment, the softening method of the present invention can be performed at a temperature not exceeding 200 ° C. In one aspect of this embodiment, the softening temperature may be equal to or lower than about 180 ° C, preferably in the range of about 20 ° C to about 170 ° C, and more preferably in the range of about 20 ° C to about 150 ° C.

Vulcanization method

The method of the present invention can perform the vulcanization step in various ways. For example, in the case of extrusion, the extruded rubber can be vulcanized immediately after extrusion, or placed in an oven, a heating chamber, a hot air chamber or a steaming chamber, or an autoclave to pass heat, heat Air or steam promotes this vulcanization. In one embodiment, the time window of the vulcanization process may be equal to or lower than about 20 minutes, preferably equal to or lower than about 1 to 20 minutes, and more preferably equal to or lower than about 2 to 20 minutes.

In one embodiment, the vulcanization step according to the present invention is performed at a temperature of not more than 200 ° C in contact with the diene rubber and the surrounding atmosphere. In one aspect of this embodiment, the curing temperature may be equal to or lower than about 180 ° C, preferably in the range of about 20 ° C to about 170 ° C, and more preferably in the range of about 60 ° C to about 160 ° C. For example, the vulcanization can be performed by a low temperature oven or a steam autoclave or chamber at about 110 ° C to 160 ° C, and more preferably at about 120 ° C to 140 ° C.

Crosslink density

In one embodiment, the diene rubber article prepared by the method of the present invention may preferably have a good crosslinking density. The preferred density value depends on the hardness of the rubber, and may be, for example, about 10 ^-5 mol / cc at a hardness of about 60; or about 10 ^-6 mol / cc at a hardness of about 20 to 30.

The crosslink density can be calculated from the equilibrium volume expansion data in n-heptane at 30 ° C and the simplified Flory-Rehner equation (notation of Kraus). The crosslinking density ν _e can be calculated by the following formula: ν _e =-(1 / V _S ) * {(ln (1-V _r ) + V _r + μV _r ² ) / {V _r ^1/3- (2V _r / f)}

Where μ = μ ₀ + βV _r , μ ₀ and βV _r are the characteristic constants of the polymer in question; Vr is the volume fraction of the polymer in the expanded vulcanizate, and Vr = (the volume of the polymer) / {(the volume of the polymer (Volume) + (volume of solvent)}; VS is the molar volume of n-heptane = 148.1; VO is the volume fraction of the polymer in an unexpanded state; and f = 4 (in the case of a tetrafunctional network structure) .

Transparency of formed objects

In one embodiment, the diene rubber article prepared by the method of the present invention is preferably transparent. If a 2 mm sheet is measured according to JIS K6252, considering sufficient transparency, the object may preferably have a turbidity of less than about 20%, preferably has a turbidity of about 18%, and more preferably has a turbidity of about 15% or less. Haze, even more preferably, has a haze of about 10% or less. If the turbidity is about 20% or higher, the transparency of the object may be too low to meet the market's practical and aesthetic requirements.

In one embodiment, in consideration of sufficient mechanical characteristics, the diene rubber article of the present invention may have a modulus of about 0.5 MPa or higher, more preferably about 1.0 MPa or higher, and more preferably a modulus of about 2.0 MPa or higher. . If the modulus is too low (for example, where M100 is below about 0.5 MPa), the article may lack sufficient mechanical properties.

In one embodiment, the diene rubber article of the present invention may have a type A durometer hardness of about 30 or higher, preferably about 30 to 70, more preferably about 40 to 70, and even more preferably 50 to 70. . In the case where the article of the present invention is incorporated into a product intended for use in a harsh environment, such as a rubber tire, the hardness of the A-type durometer may preferably be about 60 to 70. The hardness of the A-type hardness tester of the object of the present invention measured at 30 seconds may be the A-type hardness measured at 0 seconds Approximately 80% or more of the hardness, preferably approximately 90% or more of the hardness of an A-type hardness meter measured at 0 seconds, and more preferably approximately the hardness of an A-type hardness meter measured at 0 seconds 95% or higher.

In one embodiment, the breaking tensile force (Tb) of the diene rubber article of the present invention may be about 1.5 MPa or higher, preferably about 2.0 MPa to 15 MPa, more preferably about 3.0 MPa to 15 MPa, and even more It is preferably about 5.0 MPa to 15 MPa. If Tb is too low (for example, below about 1.5 MPa), the article may be too fragile to withstand external forces.

In one embodiment, the elongation at break (Eb) of the diene rubber article of the present invention may be about 150% or higher, preferably about 20% or higher, more preferably about 250% or higher, and More preferably, it is about 300% or more. If Eb is too low (eg, below about 150%), the article may lack sufficient flexibility.

In one embodiment, the tear strength of the diene rubber article of the present invention may be about 10 N / mm or more, as measured in accordance with JIS K6252 using a 2 mm thick sample sheet, preferably about 10 N / mm to 50 N / mm, more preferably about 20 N / mm to 50 N / mm. If the tear strength is too low (for example, below about 10 N / mm), the article may lack sufficient durability.

In one embodiment, the diene rubber article of the present invention may preferably have a low metal content, such as Fe, Li, Al, Nd, and Ti, especially when the product directly contacts the body (for example, medical grade or food Pipe, conduit or tube).

In one embodiment, the diene rubber article of the present invention is preferably made of two or more rubber components having a similar refractive index and thus good transparency. For example, the difference (absolute value) between the refractive indices of the two rubber components may be about 0.100 or less, preferably about 0.050 or less, more preferably about 0.020 or less, and even more preferably About 0.010 or less, about 0.005 or less, about 0.002 or less, or about 0.001 or less.

In one embodiment, according to JIS K7361-1, the article of the present invention may have about 88% or higher, preferably about 89% or higher, more preferably about 90% or higher, and even more preferably Has a total light transmittance of about 91% or higher. If the total light transmittance is below about 88%, the object may lack sufficient transparency.

The articles of the invention can be used in any industrial diene rubber field. By way of example, the item may include, but is not limited to, pipes, tubes, hoses, tires, artificial nozzles, films, sheets, vibration or construction materials, food trays, wires, cables, and profile extrusion products, such as Grooves and frames. The article can be used in medical, biological or food-grade applications.

Examples

Examples of the present invention will now be further described with reference to the following working examples, comparative examples, and reference examples; however, the scope is not limited to these examples.

Program

The materials used in the preparation examples are shown in the table below. In the following, the amount of each component is written in phr.

Rubber substance

Cariflex IR307: lithium-catalyzed polyisoprene manufactured by Kraton Polymers; cis content: about 87% to about 91%; refractive index at 23 ° C: 1.519; density: 0.91 g / cm ³ .

Cariflex IR310: Lithium-catalyzed polyisoprene manufactured by Kraton Polymers; cis content: about 87% to about 91%; refractive index at 23 ° C: 1.519; density: 0.91 g / cm ³ .

RB-820: syndiotactic 1,2-polybutadiene manufactured by JSR; crystallinity: 25%; melting point: about 95 ° C; density: 0.906 g / cm ³ .

RB-810: syndiotactic 1,2-polybutadiene manufactured by JSR; crystallinity: 18%; density: 0.901 g / cm ³ .

NR # 1: natural rubber, wrinkled tobacco film # 1 made in Thailand; density: about 0.91 g / cm ³ .

SBR1502: styrene butadiene rubber manufactured by Astlett Rubber Inc .; density: 0.94 g / cm ³ ; Menner viscosity: 52.

EPT3091: EPDM rubber manufactured by Mitsui Chemicals Inc .; density: 0.87 g / cm ³ ; Menner viscosity: 57.

peroxide

Kayalene 6-70: 1,6-bis (third butyl-peroxycarbonyloxy) hexane manufactured by Kayaku Akzo Corporation.

Kayacarbon BIC-75: isopropyl peroxide, manufactured by Kayaku Akzo Corporation Tert-butyl carbonate.

Trigonox 117: Tributyl peroxy 2-ethylhexyl carbonate manufactured by AkzoNobel.

Perhexa 25B: 2,5-dimethyl-2,5-bis (third butylperoxy) hexane manufactured by NOF Corporation.

Perbutyl H-69: a third butyl hydrogen peroxide manufactured by NOF Corporation.

Other additives

Lauric acid

Irganox 1010 (manufactured by BASF)

Irganox PS800 (manufactured by BASF)

EGDMA (ethylene glycol dimethacrylate)

S (sulfur)

Unless otherwise stated, the amount of material is written in phr.

The material shown above was formed into a raw rubber compound by the following method using a 5-inch mixing roller (191-TM test roller manufactured by Yasuda Seiki).

(a.) The roller is heated to a temperature close to the melting point of the test rubber substance. The test rubber substance is hung on a roller and then pressed and wound on the roller.

(b.) The pressed rubber substance is uniformly kneaded on the roller.

(c.) Add the additives other than the vulcanizing agent to the uniform rubber band obtained on the roll and knead again. If some additives have a higher melting point, the roll is heated to a higher temperature. (For example, the melting point of Irganox 1010 is 110 ° C to 120 ° C)

(d.) A vulcanizing agent is added to the rubber substance so that it is uniformly dispersed in the rubber substance.

(e.) The obtained rubber substance is cut into a band-shaped strip (composite) or a sheet having a thickness of about 2 mm and a thickness of about 3 mm and about 3 mm.

(f.) Subjecting the obtained strip or sheet to MDR (RLR-4, a type manufactured by Toyo Seiki Rheometer) to obtain the rheometer curve, which is used to estimate the appropriate vulcanization temperature and time range. These strips or sheets were then used in the following tests.

Test 1: Prepare and vulcanize roll flakes in a Gear oven or steam autoclave, and measure mechanical properties

A part of the samples (# 1, ...) and samples (# c1, ...) listed in the above table were prepared as raw compound flakes. The green sheet is put into a Gear aging oven (manufactured by Ueshima Seisakusho) or a steam autoclave, and is kept at a given temperature for a given period of time for vulcanization.

A vulcanized sample was removed from the oven and left in the surroundings for a day. These samples were then subjected to Tb, M100, M300, M500 and Eb measurements. The results are shown in the table below.

Samples # 1- # 21 exhibited good mechanical properties, while samples # c1, # c2, # c3, # c4, and # c5 had poor Tb.

Test 2: Tube extrusion test

The test strip made from the above formulation was subjected to a single screw extruder (Laboplastomill 10C100 manufactured by Toyo Seiki; screw size: φ 15mm; screw type: full thread type; compression ratio = 2.5; L / D = 20; extrusion speed: 90 to 100 rpm). The temperature is set as follows: zone 1: 95 ° C to 100 ° C; zones 2 and 3: 100 ° C; zone 4 (head die): 110 ° C to 120 ° C.

The strips are placed in the hopper of the extruder. The extrusion tube was cut and cooled for a short time. The tubes were then placed in a Gear aging oven (manufactured by Ueshima Seisakusho) and held at a given temperature for a given period of time for vulcanization.

A sample of the vulcanization tube was removed from the oven and left in the surroundings for a day. The sample was then subjected to a Tb measurement. The results are shown in the table below.

These samples have good Tb and the extruded tube will meet the industrial requirements in this technology.

Test 3: Measurement of crosslink density

In a vial, the above sample was immersed in n-heptane and allowed to swell. The solvent was then removed and the weight thus obtained was measured. Each sample is typically tested in duplicate. The crosslink density is calculated from the Flory-Rena equation explained above. The results are shown in the table below.

These samples generally have good cross-link density. Sample # c1 was completely unvulcanized and dissolved in a solvent. Samples # c2 and # c3 were not completely dissolved in the solvent, but they lacked enough Tb. In addition, the solvent containing sample # c2 became cloudy.

Test 4: Surface observation

As in Test 2 above, sample # 31 was prepared and extruded into a tube form, but the extruder temperature was set to: Zone 1, Zone 2, and Zone 3: 120 ° C; Zone 4 (head die): 120 ° C. The curing temperature in the Gear oven is 120 ° C and the curing time is 2 minutes, 4 minutes, 6 minutes, or 10 minutes. The cured sample had a smooth surface and was not tacky on it. Its image is shown in FIG. 1.

Test 5: Measurement of turbidity

To estimate the turbidity of the object of the present invention, Cariflex IR307, RB-820, lauric acid, Perhexa 25B and EGDMA were mixed and kneaded to obtain a 2 mm thick sheet. The obtained sheet was measured for turbidity and TT. The results are shown below.

Sample # a1

Cariflex IR307: 95phr

RB-820: 5phr

Lauric acid: 0.25phr

Perhexa 25B: 2phr

EGDMA: 4phr

Curing temperature: 150 ℃

Curing time: 13min.

Turbidity: 5%

TT: 91%

Sample # a2

Cariflex IR307: 80phr

RB-820: 20phr

Lauric acid: 0.25phr

Perhexa 25B: 2phr

EGDMA: 4phr

Curing temperature: 150 ℃

Curing time: 7min.

Turbidity: 5%

TT: 91%

Sample # a3

Cariflex IR307: 90phr

RB-820: 10phr

Lauric acid: 0.25phr

Perhexa 25B: 2phr

EGDMA: 4phr

Curing temperature: 160 ℃

Curing time: 10min.

Turbidity: 16%

TT: 92%

Claims (18)

A method for forming an article from a diene rubber, the method comprising the steps of: providing a raw diene rubber substance containing a 1,2-polybutadiene rubber component; and adding the raw diene rubber substance as a vulcanizing agent Peroxocarbonate; soften the diene rubber at a first temperature not exceeding 200 ° C; make the diene rubber at a second temperature not exceeding 200 ° C while bringing the diene rubber into contact with the surrounding atmosphere Vulcanization; and forming an object from the vulcanized diene rubber. The method of claim 1, wherein the peroxycarbonate is selected from 1,6-bis (third butyl-peroxycarbonyloxy) hexane, third butyl isoperoxycarbonate or peroxy2 -Ethylhexyl carbonate third butyl. The method of claim 2, wherein the 10-hour half-life temperature of the peroxide is in the range of about 20 ° C to about 190 ° C. The method of claim 3, wherein the one-minute half-life temperature of the peroxide is equal to or more than about 100 ° C. The method of claim 4, wherein the first temperature is equal to or lower than about 180 ° C. The method of claim 5, wherein the second temperature is equal to or lower than about 180 ° C. The method of claim 1, wherein the providing step further comprises: mixing a 1,2-polybutadiene rubber component with a second rubber component, wherein the second rubber component includes one selected from the group consisting of Or more: isoprene rubber (IR), butadiene rubber (BR), styrene butadiene rubber (SBR), acrylonitrile butadiene rubber (NBR), urethane rubber (U) , Ethylene propylene rubber (EPR) and natural rubber (NR); and providing the mixture as the raw diene rubber substance. The method of claim 7, wherein the isoprene rubber (IR) component includes a component selected from the group consisting of One or more of the following groups: low cis isoprene, high cis isoprene, neodymium catalyzed isoprene, lithium catalyzed isoprene, and Ziegler-Natta (Ziegler -Natta) catalyzed isoprene. The method of claim 8, wherein the amount of the 1,2-polybutadiene rubber component is about 5 to 95 parts by mass, and the limitation is that the total amount of the rubber components is 100 parts by mass. The method of claim 9, wherein the surrounding atmosphere is oxygen-containing air. The method of claim 10, wherein the softening step is performed in an extruder. The method of claim 11, wherein the vulcanization step is performed after the rubber is extruded from the extruder. The method of claim 12, wherein the method does not include adding a filler and a processing oil. The method of claim 12, further comprising the step of adding a filler. A diene rubber article manufactured by a method according to any one of claims 1 to 14. The article of claim 15, wherein the turbidity of the article is less than about 20% as measured in the form of a 2 mm thick sheet according to JIS K7136. The article of claim 15 or 16, wherein the article does not contain silica or processing oil. A diene rubber composition configured to undergo extrusion, the composition comprising: a raw diene rubber substance comprising a 1,2-polybutadiene rubber component; and a peroxy carbonate as a vulcanizing agent.